Plantlike Protists










Essential Questions



Welcome to our

Plantlike Protists Page!

This page is packed

with information

all about plantlike protists!


ÁGreen Algae

(Courtesy of Michael Guiry)


-They are producers and consumers.

-They mostly use photosynthesis,

but some eat

other protists or absorb nutrients for food

-They are known as algae. (Alga- singular)

-Algae is multicelled and singlecelled, but the

singlecelled type canít be seen without a microscope.

-Singlecelled algae that floats near the surface

of the ocean are phytoplankton.

-Most multicellular algae are seaweed or kelp.

-There are 3 main types of algae: red, brown, and green.

-There are 4 major pigments found in algae:

red, yellow-brown, green, and blue-green.

-Other types of plantlike protists are diatoms,

dinoflagellates, and euglenoids.

-Some euglenoids donít have chloroplasts, so

they eat small protist or consume nutrients.

-Characteristics that distinguish a plantlike

protists from animal like prost are:

they have chlorophyll in most of them and they

are called phytoplankton in the ocean.


I. Plantlike Protists

†††† A. Types

1.            Red Algae

a.             Group containing most of the worldís seaweeds

b.             Have chlorophyll and a red pigment that gives them their color

c.              Multicellular

d.             Live in marine waters and attach to rocks or another algae

e.             They can grow in deeper water because the red pigment lets them absorb sunlight at a deeper depth

f.                Can grow up to 260 meters underwater

g.             Grow to about a maximum of 1 meter

2.            Brown Algae

a.             The algae that live in colder climates are mostly brown algae

b.             They attach to rocks or form big floating beds in the ocean

c.              Have chlorophyll and yellowish- brownish pigment

d.             Are very large and can grow up to 60 meters in one season

e.             Since only the top gets sunlight, they make food (chlorophyll) and send it to the roots

3.            Green Algae

a.             They are green because the chlorophyll is the main pigment they have

b.             Live in water and moist soil, but can be found in melting snow and inside other organisms.

c.              Some are singlecellular and some are multicellular

d.             Multicelled grows up to 8 meters

e.             Some singlecelled live in colonies

4.            Diatoms

a.             Singlecellular

b.             Live in salt and fresh water and sometimes hold on to plants, shellfish, sea turtles, and whales

c.              Use photosynthesis

d.             Are a large portion of phytoplankton

e.             Cell walls have silica and cellulose

f.                The cells are inside a shell that fits together almost perfectly

g.             Piles of these shells over millions of years form a substance that is in toothpaste, silver polish, filters, insulation, and more.

5.            Dinoflagellates

a.             Most are single cell

b.             Live mostly in salt water, but some are found in fresh water and snow.

c.              Have 2 flagella that make the protists spin

d.             Most use photosynthesis, but some get food as consumers, decomposers, or parasites

e.             They are sometimes red and produce a strong poison

f.                When they produce very fast, they cause red tide, where the water turns red and the shellfish eat the algae, making the shellfish poisonous to all vertebrates.

6.            Euglenoids

a.             Single cell

b.             Live mostly in fresh water

c.              Have plant and animal characteristics

d.             Use photosynthesis, but when thereís not enough light, they are consumers

e.             Some donít use photosynthesis at all because they donít have chloroplast. Instead, they just eat other protists or take in nutrients

f.                Move by using flagella to push them through the water




1.             Algae- protists that convert the sunís energy into food by photosynthesis

2.             Phytoplankton- a microscopic photosynthetic organism that floats near the surface of the ocean

3.             Chlorophyll- a green pigment in chloroplast that absorbs light energy for photosynthesis

4.             Red Tide- when red and poisonous dinoflagellates reproduce really fast, causing the water to turn red; if a shellfish eats the algae, they are poisonous to all vertebrate animals, including humans